The investigations show, that the work steps of the
single changes can be divided into three categories, which
are shown in Figure 4. In the first category contains the
work steps that can be executed in parallel to other work
steps, such as the installation and removal of the
machines. Here, however, it must be ensured that
sufficient resources for the parallel implementation of the
work steps are available. The second category includes
the steps which cannot be executed in parallel to other
work steps on the basis of mutual disability, such as the
transport of the machines. The third category includes the
steps which can be combined into a single step and can be
execute together. For example, the process changes,
which must be planned and adjusted in the manufacturing
planning system for several engineering changes, can be
carried out in one step. This subdivision of the work steps
into these various categories is necessary for planning
several engineering changes. The work steps will be
organized in a task schedule on the basis of these
categories for a combined implementation of several
engineering changes.